Turner (NSQF) - 3rd SEM - Practical Contents · Shri. D.N. Srinivasa Shetty _ Junoi r Tranini g Oceiff r Govt. ITI, Bangalore -29. Shri. Chandrahasa _ Junoi r Tranini g Oceiff r Govt

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NATIONAL INSTRUCTIONALMEDIA INSTITUTE, CHENNAI

TURNER

SECTOR: Production & Manufacturing

TRADE PRACTICAL

Post Box No. 3142, CTI Campus, Guindy, Chennai - 600 032

2nd Year (Volume I of II)

NSQF LEVEL - 5

DIRECTORATE GENERAL OF TRAININGMINISTRY OF SKILL DEVELOPMENT & ENTREPRENEURSHIP

GOVERNMENT OF INDIA

Copyright Free Under CC BY Licence

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Sector : TurnerDuration : 2 - YearsTrade : Turner 2nd Year (Volume I of II) - Trade Practical - NSQF Llevel 5

First EditionFirst Reprint : January, 2019 Copies : 3,000

: September, 2018 Copies : 1,000

Rs.100/-

All rights reserved.

No part of this publication can be reproduced or transmitted in any form or by any means, electronic or mechanical, includingphotocopy, recording or any information storage and retrieval system, without permission in writing from the NationalInstructional Media Institute, Chennai.

Published by:

NATIONAL INSTRUCTIONAL MEDIA INSTITUTEP. B. No.3142, CTI Campus, Guindy Industrial Estate,

Guindy, Chennai - 600 032.Phone : 044 - 2250 0248, 2250 0657, 2250 2421

Fax : 91 - 44 - 2250 0791email : [email protected], [email protected]

Website: www.nimi.gov.in


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FOREWORD

The Government of India has set an ambitious target of imparting skills to 30 crores people, one out of every four Indians, by 2020 to help them secure jobs as part of the National Skills Development Policy. Industrial Training Institutes (ITIs) play a vital role in this process especially in terms of providing skilled manpower. Keeping this in mind, and for providing the current industry relevant skill training to Trainees, ITI syllabus has been recently updated with the help of Mentor Councils comprising various stakeholder's viz. Industries, Entrepreneurs, Academicians and representatives from ITIs.

The National Instructional Media Institute (NIMI), Chennai has now come up with instructional material to suit the revised curriculum for Turner Trade Practical 2nd Year (Volume I of II) in Production & Manufacturing Sector . The NSQF Level - 5 Trade Practical will help the trainees to get an international equivalency standard where their skill proficiency and competency will be duly recognized across the globe and this will also increase the scope of recognition of prior learning. NSQF Level - 5 trainees will also get the opportunities to promote life long learning and skill development. I have no doubt that with NSQF Level - 5 the trainers and trainees of ITIs, and all stakeholders will derive maximum benefits from these IMPs and that NIMI's effort will go a long way in improving the quality of Vocational training in the country.

The Executive Director & Staff of NIMI and members of Media Development Committee deserve appreciation for their contribution in bringing out this publication.

Jai Hind

RAJESH AGGARWALDirector General/ Addl. Secretary

Ministry of Skill Development & Entrepreneurship,Government of India.

New Delhi - 110 001


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PREFACE

The National Instructional Media Institute (NIMI) was established in 1986 at Chennai by then DirectorateGeneral of Employment and Training (D.G.E & T), Ministry of Labour and Employment, (now under DirectorateGeneral of Training, Ministry of Skill Development and Entrepreneurship) Government of India, with technicalassistance from the Govt. of the Federal Republic of Germany. The prime objective of this institute is todevelop and provide instructional materials for various trades as per the prescribed syllabi (NSQF LEVEL 5)under the Craftsman and Apprenticeship Training Schemes.

The instructional materials are created keeping in mind, the main objective of Vocational Training underNCVT/NAC in India, which is to help an individual to master skills to do a job. The instructional materials aregenerated in the form of Instructional Media Packages (IMPs). An IMP consists of Theory book, Practicalbook, Test and Assignment book, Instructor Guide, Audio Visual Aid (Wall charts and Transparencies) andother support materials.

The trade practical book consists of series of exercises to be completed by the trainees in the workshop.These exercises are designed to ensure that all the skills in the prescribed syllabus are covered. The tradetheory book provides related theoretical knowledge required to enable the trainee to do a job. The test andassignments will enable the instructor to give assignments for the evaluation of the performance of a trainee.The wall charts and transparencies are unique, as they not only help the instructor to effectively present atopic but also help him to assess the trainee's understanding. The instructor guide enables the instructor toplan his schedule of instruction, plan the raw material requirements, day to day lessons and demonstrations.

IMPs also deals with the complex skills required to be developed for effective team work. Necessary carehas also been taken to include important skill areas of allied trades as prescribed in the syllabus.

The availability of a complete Instructional Media Package in an institute helps both the trainer andmanagement to impart effective training.

The IMPs are the outcome of collective efforts of the staff members of NIMI and the members of the MediaDevelopment Committees specially drawn from Public and Private sector industries, various training institutesunder the Directorate General of Training (DGT), Government and Private ITIs.

NIMI would like to take this opportunity to convey sincere thanks to the Directors of Employment & Trainingof various State Governments, Training Departments of Industries both in the Public and Private sectors,Officers of DGT and DGT field institutes, proof readers, individual media developers and coordinators, but forwhose active support NIMI would not have been able to bring out this materials.

R. P. DHINGRAROTCERID EVITUCEXE 230 006 - iannehC


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ACKNOWLEDGEMENTNational Instructional Media Institute (NIMI) sincerely acknowledges with thanks for the co-operation and

contribution extended by the following Media Developers and their sponsoring organisations to bring out this

Instructional Material (Trade Practical) for the trade of Turner (NSQF Level-5) under the Production &

Manufacturing Sector for ITIs.

MEDIA DEVELOPMENT COMMITTEE MEMBERS

Shri. A. Vijayaraghavan _ Assistant Director of Training (Retd.)ATI, Chennai-32.

Shri. R. Purushothaman _ Assistant Director (Retd.) (Mechanical Engg)MSME, Chennai-32.

Shri. M. Sampath _ Training officer (Retd.)CTI, Chennai-32.

Shri. A. Natarajan _ Training OfficerGovt. ITI, Coimbatore.

Shri. N. Sampath _ Assistant Training OfficerGovt. ITI, Ambathur.

Shri. Dhayalamoorthy _ Assistant Training OfficerGovt. ITI, Tiruvannamalai.

Shri. Sampath Kumar _ Assistant Training OfficerGovt. ITI, Chennai-32.

Shri. S. Balasubramanian _ Assistant Training OfficerGovt. ITI, Chennai-32.

Shri. D.N. Srinivasa Shetty _ Junior Training OfficerGovt. ITI, Bangalore -29.

Shri. Chandrahasa _ Junior Training OfficerGovt. ITI, Mysore - 570007.

Shri. Srinivasa Naik _ Junior Training OfficerGovt. ITI, Mysore - 570007.

Shri. K. Srinivasa Rao _ Joint Director,Co-ordinator, NIMI, Chennai-32.

Shri. V. Gopalakrishnan _ Assistant Manager,Co-ordinator, NIMI, Chennai - 32.

Shri. N. Sundararajan _ Assistant Manager,Co-ordinator, NIMI, Chennai - 32.

NIMI records its appreciation for the Data Entry, CAD, DTP operators for their excellent and devoted services inthe process of development of this Instructional Material.

NIMI also acknowledges with thanks the invaluable efforts rendered by all other NIMI staff who have contributedtowards the development of this Instructional Material.

NIMI is also grateful to everyone who has directly or indirectly helped in developing this Instructional Material.


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INTRODUCTION

TRADE PRACTICAL

The trade practical manual is intented to be used in workshop . It consists of a series of practical exercies tobe completed by the trainees during the Third Semester course of the Turner trade supplemented andsupported by instructions/ informations to assist in performing the exercises. These exercises are designedto ensure that all the skills in the prescribed syllabus are covered.

The manual is divided into four modules. The distribution of time for the practical in the four modules are givenbelow.

Module 1 Form Turning 125 HrssrH 571stnemhcattA fo esU2 eludoM

Module 3 Boring 100 Hrs

srH 521daerhT tratS itluM4 eludoM

Total 525 Hrs

The skill training in the computer lab is planned through a series of practical exercises centred around somepractical project. However, there are few instance where the individual exercise does not form a part of project.

While developing the practical manual a sincere effort was made to prepare each exercise which will be easyto understand and carry out even by below average traninee. However the development team accept that thereif a scope for further improvement. NIMI, looks forward to the suggestions from the experienced training facultyfor improving the manual.

TRADE THEORY

The manual of trade theory consists of theorectical information for the Third Semester course of the TurnerTrade. The contents are sequenced accoring to the practical exercise contained in the manual on Tradepractical. Attempt has been made to relate the theortical aspects with the skill covered in each exercise to theextent possible. This co-relation is maintained to help the trainees to develop the perceptional capabilities forperforming the skills.

The Trade Theory has to be taught and learnt along with the corresponding exercise contained in the manualon trade practical. The indicating about the corresponding practical exercise are given in every sheet of thismanual.

It will be preferable to teach/learn the trade theory connected to each exercise atleast one class beforeperforming the related skills in the shop floor. The trade theory is to be treated as an integrated part of eachexercise.

The material is not the purpose of self learning and should be considered as supplementary to class roominstruction.


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CONTENTS

Exercise No. Title of the exercise Page No.

Module 1 : Form Turning

3.1.88 Form Turning practice (By hand) 1

3.1.89 Resharpening of form tool using bench grinder 4

3.1.90 Machine handle turning by combination feed 6

3.1.91 Turn Morse Taper Plug (Different numbers) 9

3.1.92 Make Revolving Tail stock centre (Bush Type) 14

3.1.93 Make Morse Taper Sleeve & Check by Taper Plug guage 17

3.1.94 Make Mandrel & Plug gauge 20

Module 2 : Use of Attachments

3.2.95 Setting & Turning operation using face plate 22

3.2.96 Making Angle plate using Face plate 29

3.2.97 Holding and Turning of crank shaft 31

3.2.98 Turning of long shaft (using steady rest) 34

3.2.99 Use of attachments on lathe for different operations 38

3.2.100 Turning standard Stub Arbor (ISO 40) With accessoriescollar, Tie rod & Lock nut 40

Module 3 : Boring

3.3.101 Perform eccentric boring (Male & Female eccentric fitting) 45

3.3.102 Position boring using tool makers button 54

3.3.103 Boring and stepped boring 58

3.3.104 Cutting helical grooves (in bearing/bushes) 60

3.3.105 Turning & Boring of Split bearing (Using boring bar & Fixture) 61

Module 4 : Multi Start Thread

3.4.106 Cutting Thread of 8 & 11 TPI 63

3.4.107 Multi start thread cutting BSW (External & Internal) 65

3.4.108 Multi start thread cutting (metric) (External & Internal) 70

3.4.109 Multi start square thread cutting (External and Internal) 73

3.4.110 Making Half Nut as per standard lead screw 77


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LEARNING/ ASSESSABLE OUTCOME

On completion of this book you shall be able to

• The trainee understand Form tool - Function - Uses, Calculation ofRake of clearance angle of lathe tools, tool setting, Jigs andFixtures.

• Identify cutting tool Materials and its constituents - types.

• Check the taper with Sine bar, calculation involved.

• Understand cutting speed - Feed - Turning time - Depth of cut indifferent turning operation.

• Set & produce components on irregular shaped Job using differ-ent lathe accessories and attachments.

• To perform different boring operation and Female eccentric fittingwith appropriate accuracy.

• Calculate to set machine setting to produce different complexthreaded components and check for functionality.


SYLLABUS

htnoM xiS :noitaruD 2nd Year (Volume I of II)

WeekNo.

Ref. LearningOutcome

Professional Skills(Trade Practical)

with Indicative hours

Professional Knowledge(Trade Theory)

53

54-55

56

Plan & set themachine parameter toproduce precisionengineeringcomponent toappropriate accuracyby performingdifferent turningoperation.[Appropriateaccuracy - ±0.02mm/(MT - 3) (proofturning); Differentturning operation –Plain turning, taperturning, boringthreading, knurling,grooving, chamferingetc.]

88. Form turning practice byhand. (8 hrs.)

89. Re-sharpening of form toolsusing bench grinder. (2 hrs.)

90. Tool machine handle turningby combination feed. (15 hrs.)

Form tools-function-types anduses,Template-purpose & use. Dialtest indicatorconstruction& usesCalculation involving modifiedrake andclearance angles of lathe toolat above andbelow the center height.Subsequent effect oftool setting.Jig and fixture-definition, typeand use. Chipbreaker on tool-purpose andtype

-do-

-do-

91. Turn Morse taper plug(different number) andcheck with ring gauge/ suitable MT sleeve. (25hrs.)

92. Make revolving tail stockcentre- Bush type (C-40).(Proof machining) (25 hrs.)

Cutting tool material-H.C.S.,HSS, Tungsten.Carbide, Ceramic etc, -Constituents andtheir percentage. Tool life,quality of acutting material.

93. Make Morse taper sleeveand check by taper pluggauge. (25 hrs.)

Checking of taper with sin barand rollercalculationinvolved

-do- 94. Make mandrel/ plug gaugewith an accuracy of±0.02mm using tungstencarbide tools includingthrow-away tips. (25 hrs.)

Cutting speed, feed, turning time,depth ofcut calculation, cutting speedchart (tungstencarbide tool) etc. Basicclassification oftungsten carbide tips.

57


58-59

60-61

-do-

-do-

62

63-64

65

Set & Producecomponents onirregular shapedjobusing differentlatheaccessories.[DifferentLathe accessories:-Face plate, angleplate]

95. Setting and turning operationinvolving face and angle plate(25 hrs.)

96. Make angle plate using faceplate. (25 hrs.)

Accessories used on face plate –their uses.Angle plate-its construction & use.Balancing-its necessity.Surface finish symbols used onworkingblueprints- I.S. system lapping,honing etc.

Plan and set themachine using latheattachment toproducedifferent utilitycomponent/ item asper drawing.[Different utilitycomponent/ item –Crank shaft (singlethrow), stub arbourwith accessoriesetc.]

97. Holding and truing ofCrankshaft – single throw(Desirable). (50 hrs.)

Preventive maintenance, itsnecessity,frequency of lubrication. Preventivemaintenance schedule., TPM(Total Productive Maintenance), EHS(Environment, health, Safety)Marking table-construction andfunction.Angle plate-construction, eccentricitychecking.

98. Turning of long shaft usingsteady rest (within 0.1 mm).(25 hrs.)

Roller and revolving steadies,Necessary, construction, uses etc.

99. Use of attachments on lathefor different operations. (25hrs.)

100. Turning standard stub arborwith accessories collar, tierod, lock nut. (25 hrs.)

Different types of attachmentsused in lathe.Various procedures of threadmeasurement thread screw pitchgauge.Screw thread micrometer,microscope etc.

Set the machiningparameters andproduce & assemblecomponents byperforming differentboring operationswithan appropriateaccuracy. [Differentboring operation –eccentric boring,stepped boring;appropriateaccuracy- ±0.05mm]

101. Perform eccentric boringand make male & femaleeccentric fitting. (15 hrs.)

102. Position boring using toolmaker’s button. (10 hrs.)

Tool maker’s button and its parts,construction and uses, telescopicgauge its construction and uses.


-do-

-do-

-do-66

67-68

69

103. Boring and stepped boring (within ± 0.05 mm) (15 hrs.)

104. Cutting of helical grooves in bearing and bushes (Oil groove) (10 hrs.)

Inside micrometer principle,construction graduation, reading,use etc. (Metric & Inch.)

105. Turning & boring of split bearing – (using boring bar and fixture ) (50 hrs.)

Care for holding split bearing.Fixture and its use in turning

106. Cutting thread of 8 and 11 TPI. (25 hrs.)

Calculation involving fractionalthreads. Odd & even threads

-do-

-do-

-do-

-do-

70 107. Multi start thread cutting (B.S.W.) external & internal. (25 hrs.)

Multiple thread function, use,different between pitch & lead,formulate to find out start, pitch,lead. Gear ratio etc.

108. Multi start thread cutting (Metric) (External & internal). (25 hrs.)

Indexing of start - differentmethods toolshape for multi-start thread.Setting of a lathecalculation for required changewheel

109. Multi-start thread cutting, square form (Male & Female). (25 hrs.)

Calculation involving shape oftool, change wheel, core dia etc.Calculation involving shape, sizepitch, core dia. Etc.

Helix angle, leading angle &following angles.Thread dimensions-tool shape,gear, gear calculation, pitch,depth, lead etc.

110. Make half nut as per standard lead screw. (25 hrs.)

71

72

73

Implant training / Project work (work in ateam)1. Pedestal bearing2. crank shaft3. arbor with clamping nut4. mandrel with jaw5. Eccentric with connecting rod6. Taper mandrel with sphere7. Lever Handle

Revision

Examination

74-75

76-77

78


14.

Plan and performbasicmaintenanceof lathe & grindingmachine andexamine theirfunctionality.

13. 85. Balancing, mounting &dressing of grinding wheel(Pedestal). (5 hrs.)

86. Periodical lubricationprocedure on lathe. (10 hrs.)

87. Preventive maintenance oflathe. (10 hrs.)

Lubricant-function, types, sourcesof lubricant. Method of lubrication.Dial test indicator use forparallelism and concentricity etc. inrespect of lathe work Grindingwheel abrasive, grit, grade, bondetc.

In-plant training / Project work1. Drill extension socket2. conical brush3. V-belt pulley4. Tail Stock Centre (MT – 3)5. Taper ring gauge6. Sprocket7. Socket spanner

Revision

Examination

15.

16.

Note: -1. Some of the sample project works (indicative only) are given against each semester.2. Instructor may design their own project and also inputs from local industry may be takenfor designing such new project.3. The project should broadly covered maximum skills in the particular trade and mustinvolve some problem solving skill. Emphasis should be on Teamwork: Knowing thepower of synergy/ collaboration, Work to be assigned in a group (Group of at least 4trainees). The group should demonstrate Planning, Execution, Contribution andapplication of Learning. They need to submit Project report.4. If the instructor feels that for execution of specific project more time is required than hemay plan accordingly to produce components/ sub-assemblies in appropriate time i.e.,may be in the previous semester or during execution of normal trade practical.5. More emphasis to be given on video/real-life pictures during theoretical classes. Somereal-life pictures/videos of both conventional & CNC turning operation, production ofdifferent components, turning of complex job, etc., may be shown to the trainees to give afeel of Industry and their future assignment.


1

Production & Manufacturing Exercise 3.1.88Turner - Form Turning

Form Turning practice (By hand)Objectives: At the end of this exercise you shall be able to• manipulate the compound rest and cross slide for turning sphere• use of Dial test indicator for truing a job• check radius by using Radius gauge/Templete.

Job Sequence

• Form turn the sphere of 25 mm diameter,manipulating the cross-slide and compound slide.

• Form R 2.5 mm radius for a width of 5 mm as perdrawing.

• Check the turned sphere with a template.

Do not use radius gauge while the job isrotating, so also the fillet gauge.Use appropriate speed and feed according tothe diameter.Clean and oil the machine after the job isfinished.

• Hold the job in a 4-jaw chuck and true it by a scribingblock.

• Set the turning tool (R.H) to centre height.

• Face one end.

• Turn dia. 22 mm x 43 mm long.

• Set the radius tool and turn radius R4 and check withradius gauge.

• Reverse the job and true it by using dial test indicatoron dia 22.

• Face the other end and maintain total length of70 mm.


2

Skill Sequence

Free hand form turningObjectives: This shall help you to• turn concave and convex forms, coordinating the carriage and cross-slide movements manually.

Note: To produce a concave form easily andaccurately, use a tool bit having a radius asclose as possible to the desired form.

Turning Concave form (Fig 1): Set the lathe speed asnear as possible to the normal turning speed withoutproducing chatter.

Move the carriage to bring the edge of the radius tool bitclose to the start of the concave form.

Place one hand on the carriage hand wheel and the otherhand on the cross-slide handle.

Slowly turn the carriage hand wheel, feeding the tool bittowards the centre of the form while with the other handturn the cross-sliide handle clockwise, moving the tool intothe work.

Co-ordinate the amount of carriage movement in relation tothe cross-slide to the desired form. For this, practice isrequired.

Take successive cuts from each side, always starting atthe large end of the form and working towards the centre.It is wise to take a light out until proper coordintion betweenthe carriage and cross-slide is attained.

Check the small diameters of the form with a caliper andthe form with a radius gauge.

Note: If a radius gauge is not available, obtaina piece of steel rod having the correct diameter.Use its circumstance to check the profile.

Cut the form close to the diameter.

With a half round file, remove the marks and finish the form.

Improve the surface finish with an abrassive cloth.

Turning a convex form (Fig 2): The same procedure thatwas adopted to machine a concave form can be used toproduce a convex form. The following steps outline theprocedure for machining 25 mm radius convex surface ona workpiece.

Using a round nose tool bit, take cuts starting at the 25 mmline and feeding towards the end of the work and centre.

Note: For the first half of the raius the carriagemust be moved faster than the cross-slidehandles. From this point to the end of the workthe cross-slide handle must be moved fasterthan the carriage hand wheel.

Take successive cuts, always starting at the outsidediameter and cutting towards the face centre.

Check the accuracy of the form with a radius gauge.

Machine the radius as close to the size and shape aspossible.

With a suitable file remove the rough machining marks andfinish the form.

Production : Turner (NSQF Level-5) : Exercise. 3.1.88


3

Setting using dial test indicatorObjectives: This shall help you to• using a Dial test indicator for truing a job.

- Set the job in four jaw chuck using dial test indicator.(Fig 1)

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- Mount the dial stand on the machine table.

- Fix the dial and touch on the job.

- Move the dial and rotate the job.

- Check the trueness of the job with the indicator at zeroposition.

- Incase difference reading the jaws adjust and rotate thechuck.

- The dial moving at A and B are the same reaching atzero.



4


Resharpening of form tool using bench grinderObjectives: At the end of this exercise you shall be able to• practice the tool movement for grinding a radius form.• checking of radius using gauge/template.


5

Job SequenceSafety• Make sure the grinding wheel guards are in place.

• Wear safety goggles.

• Check the wheel for glazing/loading.

• Adjust the tool rest close to the wheel.

• Before attempting to grind the tool, stand on a side andstart the machine.

To grind convex profile• Place the heel of the tool on the support.

• Tilt the shank about 5° to 7°.

• Hold the middle part of the tool with the left thumb andthe forefinger symmetrical to the right hand side. (Fig 1)

• Move the left hand left to right with the right hand as apivot, and grind half the slide of the nose.

• Changing the position of the hand, grind the other halfside of the nose.

• Hold the base of the tool tip with the right thumb andforefinger and hold the shank by the left hand and filethe rake surface by pressing the tool against the wheelface. (Fig 2)

• Hold the tool as shown in Fig 3. Tilt the base of the toolto about 5° to 7°, press the cutting edge surface to thegrinding wheel parallel to its outer periphery and grindthe side cutting edge and side clearance.

• Hone the ground surface with an oilstone.



6


Machine handle turning by combination feedObjectives: At the end of this exercise you shall be able to• make template to the given profile• use a dial test indicator for truing a job• check the form/profile by using template.


7

Job SequenceTASK 1 : Making template

• Mark the given sheet to the required size (keeping2 mm excess on length & width) i.e., 91 x 62

• Take a cardboard sheet & draw the profile.

• Cut the profile using a scissor.

• Paste the cordboard sheet to the prepared metal sheet.

• Punch as per the profile using dot punch for reference.

• Now by using straight snip & curved snips cut as per theprofile pasted to it (leaving atleast 0.5 mm stock forfinishing.

• Finish the profile by using smooth file

• File & maintain dimension as per drawing.

• Flattern the job by using mallet.

• Check squareness with try square.

− − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −


TASK 2 : Form turning

• Hold the job in four jaw chuck projecting 40 mm length(Approximately)

• True it by using universal surface gauge.

• Set the facing tool to the correct centre height.

• Face finish the end.

• Set the RH Turning tool to the correct centre height.

• Turn to dia 18 mm for a length of 33 mm.

• Reverse the job by holding on dia 18 mm by gripping fora length of 20 mm.

• Set the dial test indicator & true it for Ø 18 mm.

• Set the facing tool & face the end to maintain a lengthof 102 mm.

• Set the form tool & turn to a given profile gradually bytaking several rough cuts by combined feed method.

• Check the profile by using template (prepared byTask 1) & finish the job.

Avoid overhang of the cutting tool.Use plenty of coolant while machining.Give appropriate speed & feed according to thediameter.

• Reverse the job by holding on dia 18 for a length of 10mm.

• True it by using dial test indicator.

• Set the RH Turning tool & turn Ø 9.85 mm for a lengthof 18 mm.

• Make chamfer of 1.5 x 45

• Make a groove of 5 mm width and 2 mm length.

• Form M10 thread by using dia (By using split dia ofusing adjustable screw plate dia)

• Check for M10 standard (by thread plug gauge)

− − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −

Skill Sequence

Form turning by cross-slide and compound restObjectives: This shall help you to• turn a given form manipulating cross-slide and compound rest• check the profile with template.

Form turning to suit templateTurn to shape of profile gradually by taking several roughingcuts, using the cross-slide and the compound slidesimultaneously.(Figs 1 & 2)

Turn wherever possible from small diameter to larger dia.(Fig 3)


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Finish turn the plain step after form turning. (Fig 4)

A simple sheet metal template may be used to check theform. (Fig 5)

General informationForm tools have a much longer cutting edge than ordinaryturning tools.

The tool should be in a very good condition. Care must betaken to ensure maximum rigidity of the tool and workpiece.Slower speed must be used.


9


Turn Morse Taper Plug (Different numbers)Objectives: At the end of this exercise you shall be able to• use of different cutting tool material• setting of taper turning attachment to turn taper (for Task 1)• using a taper ring gauge• turn taper of compound slide swivel base method (for Task 2).


10

Job SequenceTASK 1 & 2 : Turning morse taper

• Set the job in four jaw chuck. Projecting (l1- l2 + 10mm)outside the chuck.

• True it by universal surface gauge.

• Set the carbide tip tool to the correct centre.

(For facing - offset facing tool ISO 3 F 25 P 30

or

For facing & turning in one tool - ISO 5 F 25 P 30 offset& turning & facing tool

For turning - offset side cutting tool ISO 5 F 25 P 30)

• Set the spindle speed as per the cutting speed chart.

• Face one end.

• Turn dia (d2) for a length equal to (l1 - l2 ).

• Step turn dia (d2 - 0.2) for a length of l3 (for knurling).

• Form grooving (one end R2 & another end squareshoulder) after leaving l3 from the end & maintain dia(d2- 2mm)

• Chamfer the two ends of dia d2. to 1 x 45°.

• Form knurling & maintain dia d2..

• Mark the job for filing space for marking by using ‘V’block with ‘U’ clamp. Vernier height gauge by placing onsuitable marking table.

• File the surface & maintain a width of d2 /2 mm.

• Reverse the job & hold on knurled dia by givingAluminium/Copper sheet as a packing.

• True the job by using dial test indicator (By dialling ondia d2step).

• Face the end to maintain a length of l1 .

• Turn dia d1 & check by using Vernier micrometer.

• Set the taper turning attachment to turn a taper of1° 26’ 16” for Task 1 and

• Set the compound slide swivel base to turn a taper ofTask 2.

• Turn taper & check the dimensions as per the drawingby using Vernier micrometer & Vernier caliper & Vernierbevel protractor.

• Remove the job & clamp it in bench vice holding onknurled dia by giving soft packing.

• File on taper end, step of by using safe edge file.

• Check the depth by using depth micrometer.

Skill sequence

Producing taper by using taper turning attachmentObjectives: This shall help you to• set the taper turning attachment to the required angle• produce taper by using a taper turning attachment.

A taper turning attachment provides a quick and accuratemeans of turning tapers.The following procedure is to be followed during turningtaper using a taper turning attachment.Check for backlash between the guide bar and the slidingblock, and adjust, if necessary.

Clean and oil the guide bar.Loosen the locking screws, then swivel the guide bar to therequired angle.

Tighten the locking screws.Adjust the base plate until the ends of the guide bar areequidistant from the cross-slide extension.Set up the cutting tool on exact centre.

Any error will result in an incorrect taper

Mount the workpiece on the chuck or between centres.

Adjust the carriage until the cutting tool is approximatelyopposite to the centre of the tapered section.Set up the cutting tool for the correct position.

Wear safety goggles

Set the required r.p.m.Feed the cutting tool in until it is about 6 mm from the worksurface.Remove the locking screws which connect the cross-slideand the cross-slide nut.Use the binding lever to connect the cross-slide extensionand sliding block.Insert a suitable plug in the hole on the top of the cross-slide to protect the cross- slide screw from dirt and metalchips.The compound slide must now be used to feed the cuttingtool into the work.



11

Move the carriage to the right until the cutting tool is about12 mm away from the right hand end of the workpiece.

This removes any play in the moving parts ofthe taper turning attachment

Switch on the lathe.Take a light cut about 2 mm long and check the end of thetaper for size.Set the depth of the roughing cut.Machine the work as with plain turning.Remove the play by moving the cutting tool 12 mm beyondthe right hand end of the work at the beginning of each cut.Check the taper for fit.Readjust the taper turning attachment, if necessary; takea light cut and recheck the taper.Finish the taper to size and fit it to the taper gauge.

Turning taper by compound slide swivellingObjectives: This shall help you to• turn the taper using a compound slide• check the taper with a vernier bevel protractor.

One of the methods of turning taper is by swivelling thecompound slide and feeding the tool at an angle to the axisof the work by hand feed. (Fig 1)

TUN31

9J1

Set and true the job turned to the bigger diameter of taper.

Set the machine to the required rpm.

Loosen the top slide clamping nuts.

Swivel the top slide to half the included angle of the taperas shown in Fig 2.

Ensure that equal pressure is exerted by thespanner for both the nuts.

TUN31

91J2

Fix the turning tool in the tool post to the correct centreheight.

Keep a minimum overhang of the tool.

Set the top slide to the rearmost position.

Position the saddle such that the tool is able to cover thefull length of the taper to be turned.

Ensure that the top slide does not travel beyond the edgeof the base.

Lock the carriage in position.

Touch the tool to the work surface during running and setthe cross-slide graduated collar to zero.

Bring the tool to clear off the work by the top slide handwheel movement.

Give a depth of cut by the cross-slide and feed the tool bythe top slide hand wheel till the tool clears from the work.



12

Feeding by the top slide must be uniform andcontinuous.Give successive cuts by the cross-slide, feedingby the top slide each time.

Check the angle of the turned job with a vernier bevelprotractor.

Adjust the swivel if there is any difference.

Continue the taper turning and finish the taper.



13

Skill sequence

Checking tapersObjectives: This shall help you to• check the taper using sine bar• check the taper using ring gauges/taper plug gauges.

Select suitable size sine bar and clean.

Calculate the height of slip gauges required for checkingthe angle.

Select minimum number of slip gauges to check requiredangle.

De-burr and clean the job.

Clean and “Wring” slip gauges together.

Position the job on the sine bar but against plate on surfaceplate as shown in Fig 1.

Keep the tapered job on the top of the sine bar and with areference diameter but against the angle plate.

Ensure that the sine bar angle plate and job areparallel to each other.

Position dial indicator on surface plate.

Place the styles to one end of workpiece taper.

Slide stylus across width of taper to check the highestpoint.

Set the indicator dial to zero position.

Check for zero reading at other end of taper.

Note amount of error.

If angle is correct, a zero reading should beobtained at both ends of taper.

Standard external tapers are checked with the help of taperring gauges and internal tapers are checked with taper pluggauge.

Select appropriate taper ring gauge/taper plug gauge.

Clean gauge and taper portion of the job.

Apply a thin line of marking medium down the length of theworkpiece taper in three positions. (Fig 2).

Carefully insert workpiece taper into gauge.

Push the gauge on taper as far as possible and feel for any‘rock’.

Apply slight pressure and turn gauge on taper (Fig 3).

Remove gauge and visually check marking medium isspread equally along and around taper.

If the marking medium is unequal, taper isincorrect



14


Make Revolving Tail stock centre (Bush Type)Objectives: At the end of this exercise you shall be able to• rough turn between the chuck and the centre• check the Bore using three point internal micormeter• maintain the square shoulder• finish turn work to an accuracy of ±0.06mm and check with a micrometer• turn taper with an accuracy of ±5’ using a compound slide• use a L.H. turning tool.


15

Job Sequence

TASK 1 : Tail Stock Centre

• Check the raw material for its size.• Hold the job in a four jaw chuck, keeping about 75 mm

outside and true.• Face the job at the overhanging end.

• Centre drill and support with the centre.

• Turn a dia. Ø 23 for maximum possible length.

• Turn a step dia. Ø 06.01.0

3.15 ++

to 35 mm length.

• Undercut to Ø 15.4 mm at 68 mm + the width of theundercut tool from face.

• Widen the undercut width to permit the L.H. tool entry.(Widen towards the chuck side)

• Fix the L.H. tool in the tool-post and position it in theundercut already made.

• Allow the tool tip to touch Ø 15.4 mm and feed the tooltowards the tailstock up to 42 mm from the right handface.

• Finish turn Ø 06.01.0

3.15 ++

• Swivel the compound slide for 30°, turn taper using aL.H. tool.

• Remove the tailstock centre and face the work to re-move the centre hole and maintain 30 mm length fromthe face.

• Turn taper at the end to form and including angles of60°.

• Part off the work maintaining a length of 62.2 mm.

• Reverse and hold the work on Ø 06.01.0

3.15 ++

mm and true.

• Face the work for a total length of 62 mm.

• Remove burrs.

• Check the taper angle with a vernier bevel protractor.

This is not an easy method of doing this work.This procedure is followed only to practise theuse of a L.H. turning tool.

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TASK 2 : Revolving Centre bush.

• Check the raw material for its size.

• Hold the job in four jaw chuck, keeping about 40 mmoutside & true.

• Face the end.

• Turn the job to Ø 33 for maximum length.

• Centre drill the job.

• Drill to dia 15 mm through hole.

• Set the boring tool & plain bore to Ø 18.012.0

3.15 ++

.

• Check the bore using three point internal micrometer.


• Assemble it with Task 1 job to check for sliding fit.

• Set the compound slide to form taper of 30°.

• Turn taper to maintain dia 23 mm & at the same timesuit with the Task 1 job.

• Adjust the taper if any changes & finish it.

• Set the parting off tool.

• Part off the job to a length of 32.2 mm.

• Set the job & face to maintain 32 mm.

• Deburr all sharp corners if any.

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Skill Sequence

Checking the bore using three point internal micrometerObjectives: This shall help you to• check the internal diameter accurately.

Checking the bore using three point internal micrometer.(Fig 1)

The component to checked Fig 2 is given below.


16 Production : Turner (NSQF Level-5) : Exercise. 3.1.92

Before taking measurement, the zero setting has to bechecked using the setting ring. (Fig 3)

The position of the anvil can be reset by loosening the barrelusing a screwdeiver provided for this purpose.

Depending on the depth of the bore thelength of themicrometer can be varied using the extension rod (Fig 4).

A set of spanners is provided for assembling anddisassembling the extension rod. (Fig 5)

The instruments are available in various sizes and forms formeasurring different sizes.

They are also available in analogue or digital read-outs.


17


Make Morse Taper Sleeve & Check by Taper Plug guageObjectives: At the end of this exercise you shall be able to• turn taper by attachment method• check the internal taper by using taper plug gauge• check the external taper by using Rollers, Slip gauge & micro meter.


18

Job Sequence• Check the raw material for its size.

• Hold the job in four jaw chuck, keeping about 125 mmoutside the chuck & True it.

• Set the tool for the correct centre height.

• Face the end.

• Turn to dia 32 mm for maximum possible length.

• Centre drill it.

• Drill to Ø 20 for a depth of 84 mm.

• Set the boring tool & plain bore to dia 20.2 mm for 84mm depth.

• Set the taper turning attachment to bore a taper holeof MT-3.

• Bore taper to maintain a given dia & depth (D1 & l2respectively).

• Check the taper with MT-3 taper plug gauge (Finishedproduct of 3.1.91)

• Now support the job with pipe centre.

• Set the grooving tool.

• Make groove to dia 24.5 mm leaving 109 mm from theface to a length of 117 + 4 mm (Parting Allowance)

• Set the taper turning attachment to turn a taper ofMT-4.

• Set the R.H turning tool & turn taper & maintain thedimensions.

• Set the parting off tool.

• Part off job for a length of 117.2 mm.

• Mark the job to make a slot & Tang portion.

• Chain drill & file the slot to maintain the given size.(7.8 mm width & 27 mm length)

• Hold/Set the MT-3 taper plug gauge, taper mandrel infour jaw chuck & true it by dial test indicator.

• File the tang portion to a thickness of 11.9 h13 & makeradius of R 8 at the step.

• Insert the prepared job to it.

• Set the facing tool & face the job to maintain a lengthof 117 mm.

• Make radius of R 20 at the face end.

• Remove the job from a taper plug gauge/taper mandrelusing a drift.

• Check the external taper by using rollers & slip gauges.

Skill Sequence

Checking a tapered bore using a taper limit plug gaugesObjective: This shall help you to• check the internal taper with taper plug gauge.

A taper limit plug gauge ensures the accuracy of the angleand the linear dimensions of the taper bore. (Fig 1)

Clean the tapered bore.

Clean the taper limit plug gauge.

Apply a thin layer of Prussian blue on the taper limit pluggauge along its length. (Fig 2)

TUN31

93H1 TU

N31

93H2

Assemble the taper plug gauge inside the tapered borecarefully with sufficient force to ensure positive contactbetween the gauge and the bore, and give one quarter twistto the plug gauge.

Carefully remove the taper limit plug gauge and check if thePrussian blue is rubbed off uniformly, atleast to about 75%of its area. This ensures the accuracy of the angle required.



19

Then once again insert the taper plug gauge inside thetaper bore and check. If the big dia. end of the bore fallswithin the ‘Go’ and ‘No-Go’ limits marked on the gauge,this ensures the dimensional accuracy of the tapered bore.(Fig 3)

TUN31

93H3



20


Make Mandrel & Plug gaugeObjectives: At the end of this exercise you shall be able to• use of carbide tip tools• turn with an accuracy of 0.02 mm• use of plain ring gauge to check dia of plug gauge.


21

Job Sequence

TASK 1 : Making of Mandrel

• Check the size of the raw material.

• Hold the job in a four jaw chuck and true it.

• Set the spindle r.p.m and face one end.

• Centre drill the end.

• Reverse and true the job.

• Face to length 160 mm and centre drill.

• Crown centre holes using the special centre drill.

• Dismount the four jaw chuck from the lathe spindleand mount the driving plate on the spindle nose.

• Clamp the job on a suitable lathe carrier and supportthe work between centres.

• Set the spindle r.p.m. and rough turn diameter to 24.16mm. to maximum possible length.

• Turn step Ø 21 for 18 mm length and chamfer 2 x 45°.

• Reverse the job and turn Ø 21 mm for 18 mm lengthand chamfer 2 x 45°.

• Set the form tool to 60° and turn taper on step dia. asshown in the sketch.

• Check the size with an outside mircometer.

• Set the taper turning attachment for the small taper.

• Adjust in such a way that 24 mm diameter at the cen-tre of the mandrel is achieved, with an acceracy of± 0.02 mm.

TASK 2 : Making of a plug gauge

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• Check the size of the raw material.

• Hold the job in four jaw chuck & true it.

• Face the end.

• Centre drill it.

• Reverse the job & true it.

• Face the end to maintain 150 mm length.

• Dismantle the chuck from the spindle & mount the drivingplate. Spindle adopter & line centre to turn the job be-tween centres.

• Set the job in between centres.

• Turn Ø 005.0001.0

30++

for a 32 mm length. (For ‘No Go’ gauge)

• Check dia with vernier micrometer.

• Make a groove to Ø 20 mm for a width to suit a R.Hturning tool leaving 16 mm from the face.

• Set the R.H turning tool & turn to dia for alength as per drawing.

• Make a groove/under cut with corner rounded as perdrawing. (12 mm width at two corners)

• Set the knurling tool & form knurling and maintain adia 20 mm.

• Reverse the job & turn Ø 021.0000.0

30−+

remaining length

(20 mm) (For Go - to the Gauge)

• Deburr all sharp corners.

• Check the dimensions as per the drawing.

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22

Production & Manufacturing Exercise 3.2.95Turner - Use of Attachments

Setting & Turning operation involving Face plate & Angle plateObjectives: At the end of this exercise you shall be able to• setting the square job on face plate• turning the job using scribing block• drill and boring


23Production : Turner (NSQF Level-5) : Exercise. 3.2.95


24

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Job SequenceTASK 1: Boring operation using face plate

• Check material size as per drawing.

• Apply marking media.

• Mark the centre using steel rule and scriber.

• Punch the centre using centre punch and hammer.

• Draw the circles of Ø 60 mm using the divider.

• Punch the identification mark using prick punch 60°and hammer.

• Clamp the workpiece on slotted face plate using boltand clamp.

• True the workpiece as per the punch mark using scrib-ing block.

• Make the centre drill and pilot hole of 8 mm.

• Enlarge the hole Ø 8 mm to Ø 20 mm, Ø 30 mm,Ø 40 mm and Ø 50 mm drills.

• Set the boring tool to correct centre height.

• Bore the drilled hole to Ø 60 mm through.

• Deburr the sharp corner of workpiece.

• Check the bore size with a vernier caliper.

TASK 2A : Fixture for clamping in face plate TASK 2B : Fixture for guiding the work

Check the raw material size.

• Hold the raw material about 5 mm outside the chuckand run true.

• Set the facing tool and face one end of job.

• Reverse and hold the workpiece and face it to maintaina total length 140 mm.

• Remove and hold workpiece and face it to maintain atotal length 140 mm.

• Face the job 4 sides squareness right angles and trueit.

• Make the drill hole and counterbore.

• Centre punch the centre.

• Drill through hole Ø 7 mm.

• Drill through hole 12 mm 2 holes.

• Mount and fix the 14 mm counterbore tool on the drill-ing machine spindle.

• Counterbore the holes to a depth 8 mm.

• Check the workpiece to verify the correctness of di

• Check the raw material size.


• Hold the raw material about 18 mm outside the chuckand run true.

• Set the cutting tool and face one end of job and turnØ 78 mm x 15 mm length.

• Reverse and hold work and face it to maintain a totallength 23 mm and turn Ø 78 mm to remaining layer.Setting of centre axis of spindle.

• Remove and hold the join in 4 jaw chuck and setting tocentre axis of spindle.

• Face 14 mm depth 4 or 5 number or cut. Maintain faceend to diameter maximum point height 70 mm.

• Mount and face the side on the Task 2A drilled positionequal to length 2 sides.

• Clamp the Task 2A and Task 2B job. (Use ‘C’ clamp)

• Drill a 5 mm 2 hole depth 15 mm guide through 7 mmdrill hole for part A.

• Dismount - Task 2A and Task 2B job.

• Cut M6 internal thread in the two Ø 5 mm drilled holes.

• Deburr the sharp corners of the workpiece.

• Fix the Task 2A and Task 2B using M6 x 30 mm lengthallen screw.

• Check the workpiece to verify the correctness of di-mensions.

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25

Turning job using face plate & angle plate (Fig 1) • Place the angle plate on the wooden board.

• Clean the face plate and angle plate throughly.

• Apply a thin film of oil on the mating area of spindleand face plate.

• Clean the angle plate.

• Locate the angle plate on the face plate and clampit properly with clamps.

• Clamp the workpiece with sufficient bolts and clampseffectively.

• Mount the face plate on lathe spindle properly.

• Set the workpiece true to centre.

• Clamp the counter weight equal for balancing therotation of spindle.

Skill Sequence

Bearing blockObjectives : This shall help you to• mark on round job for flat face• set the round job for facing in four jaw chuck.

• Check the material for its size.

• Hold the job in four jaw chuck and true it.

• Face one end of the job.

• Reverse and hold the job in chuck and true it.

• Face of other end total length maintain 23 mm. (Fig 1)

• Turn ∅78 mm and maximum length.

• Reverse the job and hold in four jaw chuck.

• Turn ∅78 mm remaining length. (Fig 2)

Use V block with clamp for hold the round rodrigidly while marking.

• Scribe the centreline on the face of round block usinga vernier height gauge.

• Scribe the 25 mm distance above from centre line andcontinue on both sides (Fig 3)

• Hold the job against 23 mm thickness (Fig 4) in four jawchuck.

• Check against the scribed line, using surface gaugefor trueness.


• Place a wooden board on the lathe bed below thespindle, to prevent any damage to the guide ways.


26

• Move the cross slide against the marked line forparallelism using surface gauge.

• Turn to finish the flat surface on the curved face jobas per drawing.

• Mark the tapped holes location as per the drawing.

• Drill ∅5 mm holes as per the drawing.

• Tap the holes with M6 tap set. (Fig 5)

Setting of face plateObjectives : This shall help you to• dismount of chuck from lathe spindle• mount of face plate.

• Switch OFF the motor.

• Place a wooden board or cradle on the lathe bed, toprevent damage to slideways (Fig 1)

• Dismantle the workholding device(Three jaw chuck)already assembled in the spindle.(Fig 2)

In addition to protecting the bed slideways itmakes fitting the chuck easier and safer.

• Ensure that the correct face plate for the lathe and forthe job in hand before attempt to mount the face plate.

• Seek assistance always when mounting large andheavy chuck (or) face plate.

• Clean the mating parts of the face plate and lathespindle as otherwise, the dirt on these surface couldresult in run out of true.

Do not use power to mount a face plate onspindle noses.



27

• Place the face plate on the wooden board. Slide itclose to the spindle nose. (Fig 3)

• Turn the spindle by hand until the key on the spindlenose lines up with the keyway in the face plate.

• Ensure the face plate mounted for its trueness formounting the workpiece.

Setting of angle plate and balancing weightObjectives : This shall help you to• set the angle plate on face plate• clamp the counterweight.

• Place a wooden board on the lathe bed to preventdamage to slide ways, due to the weight of face plate.

• Clean the face plate and angle plate seating surface.(Fig 1)

• Clamp the angle plate to position approximately to thespindle axis. (Fig 2)

• Mount the workpiece on the angle plate (Fig 3)

• Adjust the workpiece centre to spindle axis.

• Tighten the clamping bolts and nuts of angle plate andworkpiece.

• Locate and position the counterweight above theworkpiece in the slot of face plate (Fig 4)



28

• Rotate the lathe spindle by hand to check the face plateis balanced with counterweight.

• Ensure the counterweight is enough to balance theworkpiece.

• Observe the counterweight and workpiece remain inline (Fig 5)

• Check the counterweight and workpiece remain inhorizontal line (Fig 6)

• Rotate by hand to ensure the face plate is balancedby counterweight.

• Repeat to continue till the face plate is balanced byincreasing or decreasing the weight of the counterweight to set the correct position.

• Tighten all the clamping bolts and nuts rigidly beforeoperating the lathe.



29


Making Angle plate using Face plateObjectives: At the end of this exercise you shall be able to• learn the machining of two faces of an Angle plate• learn to check squareness of Angle plate• learn the method of holding odd jobs in a Face plate.

Note: The Angle plate is an useful fixture usedfor checking squareness of a component andfor marking purposes.Angle plate is generally cast and machined forfinishing it. Though milling is generally preferedfor machining, it is also possible to get itmachined in a lathe using face plate andaccessories.

Safety Precautions

1 Remove all sharp corners.

2 Use high speed and ‘O’ feed while finishing.

3 Use no coolant while machining

4 Ensure that Job is perfectly balanced & set true.


30

Job SequenceTASK 1 : Clamping the Job for one side facing

• Place a Wooden Board on the lathe bed to preventdamage to the lathe bed ways, while fixing the faceplate on to the lathe spindle.

• After fixing the Face plate, clamp the Job (Cast angleplate) to the standard angle plate already secured tothe face plate.

• Balance the angle plate by clamping suitable Counterweights.

• After ensuring that the angle plate is firmly clamped tothe face plate run the lathe spindle and check for truerunning.

− − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −

− − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −

• Set the facing tool on the tool post and take a roughfacing cut.

• Continue the facing by giving less feed till entire face ismachined to the required accuracy.

• The job after completion of one side machining is dis-mantled from the face plate and clamped for machin-ing the other face, using angle plate shown.

• Clean the slots on the Job for clamping purpose (asshown in Fig)

TASK 2 : Facing the perpendicular face

• The Angle plate is fixed to face plate is adjusted tohold clamping the Job with machined face as shown indrawing.

• Check the straightness of the Job (Machine face) par-allel to lathe bed or spindle centre. Use a dial indicatorto check the straightness.

• With Job clamped securedly, using facing tool, firsttake rough cut. (Fig 1)

• Reduce the feed and take few more face turning till theentire face is machined.

• Use finishing tool and complete the final facing increas-ing the speed of spindle, but with no feed.

• After completion, check the Job on a surface plate forsquareness.

• If squareness is not alright, re-fix the Job on the latheagain checking the squareness of one face with theface plate and take a final cut.

• Remove burrs on machined surfaces using deadsmooth file.



31


Holding and Truing of crank shaftObjectives: At the end of this exercise you shall be able to• mark eccentric axis• turn eccentric diameter• check eccentric dia run out/off set.


32

Job Sequence

• Check raw material as per drawing.

• Hold in chuck face and centre drill. (Fig 1)

• Turn to Ø 61 mm to 70 mm length.

• Remove, reverse and hold. Face to length 135 andcentre drill. (Fig 2)

• Turn to Ø 61 mm to unturned portion.

• Using ‘V’ block and height gauge mark eccentric axison both faces. Dot punch eccentric centre both sides.From eccentric centre draw circle Ø 40 both faces anddot punch. (Fig 3)

• Hold job in 4 jaw chuck align eccentric centre to m/caxis and centre drill. (Fig 4)

• Similarly on the other face also.

• Hold job bet’n in centres of eccentric axis markeccentric portion for turning. (Fig 5)



33

• Using parting to remove excess material to Ø 42.(Fig 6)

• Using LH & RH turning tool with R2 nose rod turn toØ 40 to 45 mm length and Ø 30 to 35 mm length as perdrawing. (Fig 7)

• Remove hold job bet’n centre. Rough and finish turn toØ 60 x 45 mm length Ø 40 to 35 mm length. Form radiuschamfer as per drawing.

• Place ‘V’ blocks using dial test indicator, check eccentricthrow dist of the job. Note the offset deviation.



34


Turning of long shaft (using steady rest)Objectives: At the end of this exercise you shall be able to• turn long slender jobs supported with the travelling and fixed steadies.

TUN3298E1

3.2.98

25hrs


35

Job Sequence

• Hold the job in a four-jaw independent chuck, trueand face both ends to a length of 442 mm and centredrill on both ends.

• Remove the job from the chuck and remove the chuckfrom the lathe spindle.

• Hold the job in between centres with the help of abent tail carrier.

• Turn the job for the maximum possible length diameterof 24 h8.

• Reverse job and finish full length to a diameter of 36h8.

• Turn the job to a length of 152 mm to Ø 25 mm.

• Turn the job to a length of 56.5 mm to a diameter of24 h9.

Skill Sequence

Aligning lathe centres by different methodsObjectives: At the end of this exercise you shall be able to• align themarked centre lines visually on the rear end of the tailstock• align visually the points of the live and dead centres• take trial cuts at each end of the work and check the finished diameter with a micrometer and align the lathe

centres• use a parallel test bar and a dial indicator to align the lath centres• use a micro-set adjustable centre and align the lathe centres.

Using tailstock graduations. (Fig 1) Slacken one of the adjusting screws several turns.

Tighten the other screw slowly.

Observe the direction of movement of the tailstock centre.Continue adjusting the screws until the line on the tailstockbody coincides with the line on the base plate.

Tighten the loose adjusting screw to secure the upper partof the tailstock in position.

Visual alignment.

Loosen the tailstock clamp lever or nut.

Turn the tailstock hand wheel until the tailstock spindlebarrel extends about 25 mm.

Slide the tailstock to the left until the dead centre isapproximately 10 mm from the live centre.

• Undercut 2 x 5 mm as per drawing.

• Chamfer 3 x 45° as per drawing.

• Reverse the job and turn Ø 24 mm to a length of 280mm with the support of the follower steady.

• Support the work with a fixed steady on Ø 24 mm.

• Undercut 2 mm x 10 mm as per drawing.

• Chamfer 2 x 45 mm from the collar Ø 36 h8.

Safety precautions

• Use soft packing pieces for holding the job in betweenthe job and the carrier to avoid spoilage of the finishedsurface.

• Ensure that the fingers of the follower rest is not hardpressed against the job, and it is frequently lubricated.

Loosen the clamp holding the tailstock to the bed.

Locate the adjusting screws on the tailstock body.



36

Turn the tailstock hand wheel until the points of the centresalmost touch. (Fig 2)

Place a sheet of white paper on the lathe bed under thecentres.

Look down at the top of the centres and check thealignment of the lathe centre points.

Adjust the tailstock by means of the two adjusting screwsuntil the points of both centres are in line.

Tigshten the loose adjusting screw to the upper part of thetailstock in this position.

Using the trial cut method. (Fig 3)

Stop the lathe and measure the diameters of both theturned surfaces with a micrometer.

The lathe centres are in alignment if the diameters of thetwo machined sections are the same.

If the diameters are different, the tailstock must be adjustedby one half the difference between these two diameters.This can be done by using a feeler guage of the correctthickness between the tool point and the workpiece.

Adjust towards the cutting tool, if the diameter at thetailstock end is larger.

Take anothe light cut from both machined diameters usingthe same graduated collar setting for each out. Measurethe diameter.

Continue adjusting the tailstock and taking light trial cutsuntil both diameters are the same.

Using a test bar and a dial indicator (Fig 4)

Mount the workpiece between the centres of the lathe.

Take a light cut at the tailstock end of the work, but deepenough to produce a true cylindrical surface. The cutshould be about 8 mm long.

Stop the lathe and note the reading on the cross-slidegraduated collar.

Back the cutting tool away from the work using the crossslide handle.

Move the carriage until the cutting tool is about 25 mm fromthe lathe carrier.

Make sure that the lathe carrier does not strike the topslide.

Turn the cross-slide handle slowly until the graduatedcollar is at the same setting as it was for the tailstock end.

Machine this end for a length of about 12 mm.

Clean the centres of the lathe and the centre drilled holesin the test bar.

Mount the test bar between the centres and tighten thetailstock spindle clamp.

Mound a dial indicator in the tool post or on the lathecarriage.

The contact point should be the centre of the bar and theindicator plunger should be in horizontal position.

Adjust the cross-slide so that the indicator needle registersabout one half of a revolution on the diameter at thetailstock end.

Move the carriage to the left by hand until the indicatorregisteer on the diameter at the headstock end. Note theindicator reading.

If the readings are not the same, move the carriage until theindicator again registers on the tailstock end of the diameter.

Loosen the tailstock clamp nut.

Using the tailstock screws, move the tailstock in the properdirection. The amount of movement should equal thedifference between the indicator readings.

Tighten the adjusting screw to lock the upper part of thetailstock in place.

Tighten the tailstock clamp nut and recheck to make surethat the test bare still fits snugly between the centres.

Repead these steps until the indicator readings at the twoends are the same.



37

Using micro-set adjustable centre (Fig 5)

A micro-set adjustable centre filled into the tailstockspindle provides a fast and accurate method of aligninglathe centres.

Some of these centres contain an eccentric; others containa dovetail which permits slight adjustment of the centreitself to correct the alignment.

Use either the trial cut or test bar and dial indicator methodto determine the accuracy of the lathe centre alignment.

Adjsut the micro-set adjustable centre by the amount thatthe centres are out of alignment.

A follower steady is fixed to the saddle of the lathe. As itfollows the tool it gives support just behind the cutting point.In case of the follower steady the support is continuous tothe entire length of cutting. (Fig 6)

It has usually two pads. One pad is located opposite to thecutting tool and the other pad bears the top of the workpieceto prevent it from springing up. Fig 7 shows the travellingsteady rest in position.



38


Use of attachments on Lathe for different operationsObjectives: At the end of this exercise you shall be able to• taper turning using taper turning attachment• external taper thread by taper turning attachment• internal taper thread by taper turning attachment.


39

Job SequenceTASK 1 : External taper thread


• Hold the job in a four jaw chuck keeping 10 mm out-side the chuck and true it.

• Set the tool for facing.

• Face one end and turn Ø 50 mm to Ø 50 mm length.

• Turn to Ø 40 mm to the length of 40 mm.

• Reverse the job, hold in the chuck and true it.

• Face and maintain Ø 50 mm as per drawing.

• Turn the undercut Ø 25 x 10 mm length as per draw-ing.

• Taper calculation.

• Set natural tang value = 2° 52’.

• Set the taper turning by taper turning attachment forthe 2° 52’ amount of taper.

• Taper turn engaging the power feed for a short lengthcomplete the taper turning.

• Set the change gears and norton gear box lever posi-tion for thread to 2 mm pitch.

• Cut the taper thread.

• Remove burrs.

Loosen the cross slide box nut while taper andthread cutting for yoke type attachment method.Do not remove the cross slide box nut. Whiletaper turning and threading when using tele-scope type attachment method.

TASK 2 : Internal taper thread

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• Set the tool for facing.

• Face one end and turn Ø 60 mm for maximum length.

• Reverse the job, hold in the chuck and true it.

• Face and turn to maintain total length 50 mm andØ 60 mm.

• Drill dia 10 mm through hole.

• Enlarge the through hole to Ø 25 mm.

• Fix the boring bar in the tool post and finish bore dia40 mm.

• Taper calculation.

• Set the natural tangent value 2° 52’.

• Set the taper turning attachment for the 2° 52’ amountof taper.

• Taper bore by engaging the power feed for a total length.

• Complete the taper boring.

• Set the change gear and norton gear box lever positionfor thread to 2 mm pitch.

• Cut the taper thread.

• Remove burrs.

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40


Turning standard Stub Arbor (ISO 40) With accessories collar, Tie rod & LocknutObjectives: At the end of this exercise you shall be able to• turn taper surface in between centres• boring and thread cutting• cut and files slot.


41

Job SequenceTASK 1 : Turning Stub Arbor

• Check raw material.

• Prepare machine for operation. (Cleaning, Oil level,back clash adjustment etc.,)

• Hold rawe material on 3 jaw chuck face, turn OD Ø 63x 40, turn step dia Ø 30.5x 22, centre drill/drill to tapM12 x 25 deep, provide chamfer to turn bet’n centreand chamfer corners. (Fig 1)

• Reverse andhold to face to length 125 and centre drill,drill to tap M16 x 70 deep and tap to 30 length. Providechamfer to turn. (Fig 2)

• Remove job, set machine to turn job bet’n centresarrangement.

• Arrange Taper turning attachment to 8° 17’ 50’ and turnto finish Ø 44.45. (Fig 3)

• Hold job betweeen centres and turn dia Ø 46 x 95 turnstep dia Ø 25.3 x 28 and under cut 5 x Ø 24.

• Remove and finish dia 25.3 x 25 and chamfer corners.

• Remove the job from the chuck.

• Using ‘V’ block and height gauge mark the slots 16.1mm width and 9.0 mm depth, both the sides.

• Punch the marking using prick punch 60° and ham-mer.

• Remove the excess material using chain drilling.

• File the slot for the size of 16.1 x 9mm.

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42

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TASK 2 : Turning Tie bolt


• Hold the job in three jaw chuck.

• Set th tool in correct centre.

• Face the one end make centre drill.

• Reverse the job face to the correct length.

• Hold the job between centres.

• Turn Ø 20 to required length.

• Turn Ø 16.2 to the length of 24 mm.

• Chamfer the corner.

• Cut M20 thread to the length of 80 mm as per drawing.

• Reverse job turn Ø 12 to the 20 mm depth.

• Chamfer the corner and neck.

• Cut M12 thread.

• Remove the job from the machine.

• Mark the hexagon across flat 14 mm on dia 16 mm.

• File and finish the hexagon.



43

TASK 3 : Turning Collar

• Check the raw material.

• Hold the job in 3 jaw chuck face and

• Turn to a Ø 38 upto possible lenth.

• Turn Ø 35 to the depth of 25.

• Make centre drill and pilot drill of 8, 12 and 15.

• Set the boring tool and finish the bore Ø 20+0.2

• Reverse the job face to the length of 50 mm.

• Turn Ø 30 for 20 mm depth.

• Remove and deburr the job.

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44

TASK 4 : Turning Lock nut


• Hold the job in 3 jaw chuck face and turn Ø 34.6 to adepth of 24 mm chamfer the corners.

• Reverse and hold in chuck on Ø 33 face to a length of30 mm.

• Make centre drill, pilot drills and Tap drill size for M20to full length and chamfer the corners.

• Cut internal thread of M20 using the tap.

• Remove the job from the machine make hexagon tothe depth of 24 mm.

• Deburr the job.

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45

Production & Manufacturing Exercise 3.3.101Turner - Boring

Perform eccentric boring (Male & Female eccentric fitting)Objectives: At the end of this exercise you shall be able to• marking eccentric centre & guide circle• setting eccentric axis• assembly of male and female eccentric portion• check axis mismatch.


46

Job Sequence

TASK 1: Male Part


• Clamp the facing tool, chamfering tool, turning tool andthe undercut tool in a four-way tool post to the correctcentre height.

• Hold the material in a 4 jaw independent chuck andtrue it with the help of the surface gauge.

• Face the end of the job.

• Reverse the job clamp and true it by keeping it 30 mmoutside the chuck.

• Face the job to the required length of 50 mm.

• Turn diameter Ø 80 mm with the turning tool.

• Chamfer 1 x 45° with the chamfering tool.

• Remove the job from the chuck.

• Mark the centre line and eccentric centre line accord-ing to the drawing with the help of marking tools, i.e.,surface plate, angle plate, ‘V’ Block and vernier heightgauge.

• Punch both the centre lines with the help of a centrepunch and hammer.

• Draw a guide circle of Ø 25 mm with the eccentriccentre as the centre point.

• Punch the intersecting 4 points.

• Clamp the job in a 4 jaw independent chuck on theturned diamter by keeping 30 mm outside the chuck.

Ensure that the centre lines are centered withrespect to the java.

• True the concentric circle.

• Open one jaw and tighten the opposite jaw so that thecentre of the work moves.

• Repeat the operation till the eccentric centre comes inliine with the lathe centre.

Bring the tailstock centre close to the work andensure that the eccentric centre point coincideswith the tip of the tailstock centre.

• Check and true the eccentric circle with the help of thesurface gauge for concentricity.

• Turn eccentric diameter 25.4 - 0.02 mm to a length of25 mm.

• Chamfer 1 x 45° using a chamfering tool.

• Undercut 2 x 0.5 mm and deburr by a flat, smooth file.

TASK 2: Female Part − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −


• Hold it in the independent chuck and true it with a sur-face gauge by keeping the maximum length outsidethe chuck.

• Set the facing tool and face one end.

• Set the R.H. turning tool and turn a diameter Ø 80 mmto a maximum possible length.

• Reverse and true the workpiece.

• Set the facing tool face the other end to maintain atotal length of 25 mm.

• Set the chamfering tool and chamfer the end to1.5 x 45°.

• Mark off centre for eccentric drilling and boring with aheight gauge. Use surface plate and ‘V’ Block.

• Scribe Ø 20 mm guide circle for eccentric setting.

• Centre punch and eccentric centre and punch dots forthe guide circle. Use centre punch and dot punch.

Open the jaws of the independent chuck andposition the workpiece in the jaws such thatthe centre lines are centered with respect tothe jaws. Keep the chamfered face outside thechuck.

• Bring the dead centre very cloce to the eccentric cen-tre and adjust the opposite jaws to coincide the deadcentre point with the eccentric bore centre.

• True the Ø 20 mm eccentric circle with the help of thesurface gauge. Open cut and lighten the opposite jaws.such that the centre of the Ø 20 mm moves and coin-cides with the dead centre.

• Centre drill at the eccentric hole to be drilled.

• Drill hole using three drills Ø 8, Ø 12 and Ø 16.

• Set the boring bar and bore Ø 16 mm hole toØ 25.1 mm.

• Set Ø 25.4 mm reamer and ream the hole to Ø 25.4H7.

• Use reduced speed for reaming.

• Set the chamfer tool and chamfer Ø 25.4 mm hole.

• Set the boring bar at the rear side of the hole and cham-fer.

• Ensure the fit with the finished exercise 46 (Part A)



47

.Skill SequenceMarking Eccentric centres for eccentric Turning and Eccentric boringObjectives: This shall help you to• mark the eccentric centre for turning the external diameter• mark eccentric centre for internal boring.

Marking by using ‘V’ Block, surface gauge and trysquareBefore marking, the job must be faced at both ends andmust be free from burrs and sharp edges.

Clamp the workpiece to the ‘V’ Block.

Apply marking media to both the end faces and scribehorizontal lines through the centre of the face (both ends).(Fig 1)

Unclamp and rotate the workpiece through 90°. Set thescribed line vertical using the try square, and reclamp.(Fig 2)

Scribe horizontal lines through the centre of the workpieceon both the end faces. (Fig 3)

Set the pointer of the scriber at a distance above the centreof the workpiece equal to the amount of eccentricityrequired. (Fig 4)

Scribe the line at this height on both the end faces of theworkpiece. (Fig 4)

Remove the workpiece from the ‘V’ Block.

Dot punch intersection points on both the end faces, tohave concentric and eccentric centres.

When marking off centres of a workpiece, a ‘V’Block, which can be laid on its side, may beused. This will avoid the need to unclamp theworkpiece and square.



48

Centre drill the workpiece on both the end faces on thedrilling machine.

While centre drilling make sure that the centredrill locates the centre dots accurately.

If the eccentric turning is meant for a 4 jaw chuck, scribeguide circles with eccentric centre as the centre of theguide circle, using a divider.

Marking by using angle plate, clamps, surfacegauge and try square

This marking method is used for securing the workpiece ona face-plate. Before marking, the job must be faced at bothends and it should be free from burrs and sharp edges.

Check the locating face of the workpiece for flatness. Usea straight edge and light to ensure the flatness of thelocating surfaces.

The workpiece must be clamped square to the angle plateto ensure squareness of the marking with reference to thepreviously machined faces.

Clamp the workpiece lightly to the angle plate with theoutside diameter of the workpiece touching the marking offtable. (Fig 5)

Measure the outside diameter of the workpiece; set thescriber point to half of the diameter minus bore eccentricity.

Scribe a horizontal line. (Fig 5)

Set the scriber point to mark off centre of the workpiece.Scribe a horizontal line to intersect the vertical line alreadyscribed. (Fig 7)

Unclamp, swivel the work through 90°, and with a trysquare, check that the scribed line is vertical, and reclamp.(Fig 6)

Unclamp and remove the workpiece from the angle plate.Place flat on the marking off table and with the marked offface uppermost. Dot punch intersection points.

Set the divider to the radius of the finished bore size.

Scribe a circle using the centre dot as centre point.

Unclamping of the workpiece may be avoidedby laying the angle plate on its side. In suchcases, the workpiece has to be set on the angleplate, such that the edges of the workpiecetouch the marking table in both the positionsi.e., before laying the angle plate on its sideand after laying the angle plate on its side.



49

Marking eccentricity of a job with vernier height gauge to given dimensionsObjective: This shall help you to• mark concentric and eccentric centre lines of a job by using a vernier height gauge.

The height gauge marking is more accuratethan the scribing block marking.The marking surface must be free from sharpedges and unevenness.

Clamp the finish turned rod in the ‘V’ Block with the help ofthe clamps.

Apply marking media on both faces of the job.

Set the scriber point on the top edge of the job. (Fig 1)

Move the height gauge scriber over the round surface to geta feel that the scriber bottom face is contacting the workperiphery. (Fig 1)

Lock the slides and note down the readings of the scales.

Subtract half the diameter from the reading and set theheight gauge for that reading. (Fig 2)

Scribe a horizontal line on both faces. (Fig 2)

Release the workpiece from the clamp and rotate theworkpiece through 90°. Set the line at 90° with the help ofa try square. (Fig 3)

Clamp the workpiece to the ‘V’ block.

Scribe horizontal lines on both faces with the same readingwhich is set for centre position. (Fig 4)

Add eccentricity amount to the above reading and reset theheight gauge for the new rading (Fig 4)

Scribe horizontal lines on both faces. (Fig 4)

Release the workpiece from the ‘V’ Block.

Punch mark on both sides both concentric and eccentriccentre points.



50

Truing a job for eccentric turning and eccentric boringObjectives: This shall help you to• true the job for external eccentric turning• true the job for internal eccentric boring.

Truing the eccentric job in a four jaw chuck

Open all the four jaws to give clearance to the workpiece.

Hold the workpiece up to the chuck face with the scribedlines towards the tailstock.

Insert the tailstock centre and slide the tailstock over thebed towards the headstock.

Position the workpiece until the tailstock centre locates inthe eccentric centre dot on the workpiece. (Fig 1)

Set the scriber of the surface gauge over the lathe bed.

Rotate the chuck by hand and check the running of thecentre dot or guide circle with the surface gauge pointer.

Tighten each jaw slightly in turn, after necessary adjust-ments of the two sets of opposite jaws are made.

Recheck the centre dot or guide circle with the surfacegauge.

Realign the jaws, if required.

Tighten the jaws fully.

Truing the eccentric job held on a face plate

Hold the workpiece on to the face plate.

Bring up the tailstock, locate the tailstock centre to theeccentric centre dot, apply pressure until the workpiece isheld in position. (Fig 2)

Move the tailstock centre until the pressure applied holdsthe workpiece against the chuck face.

Move the chuck jaws, tighten each jaw lightly in turn, takingcare not to shift the workpiece.

Check and adjust the position of the workpiece so that it willprotrude enough from the jaws to allow the total length ofthe eccentric portion to be machined.

Tighten the jaws.

Remove the tailstock.

Truing of eccentric job held in a four jaw chuckby using a surface gauge

Most of the eccentric truing is done with the help of guidecircles scribed on the face of the chuck and the surfacegauge. Since the guide circle has been scribed in concen-tric with the eccentric marking, truing the work to the guidecircle gives the exact centre point of the eccentric turning.

Open all the four jaws to give clearance to the workpiece.

Hold the workpiece up to the chuck face.

If the eccentric bore in the workpiece is to be through thenthe parallel bars must be placed behind the workpiece toclear off the face plate during drilling and boring.

Select suitable clamps, Tee bolts, nuts, washers andpackings as required.

Clamp the workpiece to the face plate, clamp in positionswhich will give support ie., as near to the holes as possiblebut diametrically opposite. (Fig 3)


Recheck the tightness of the clamps.

Rotate the face plate by hand and check the concentricityof the marked off bore with the help of the surface gauge.



51

Realign the job, if required.

Recheck the tightness of the clamps.

If the amount of eccentricity is great, then thecounter-balance weights must be clamped orbolted to the face plate to give a balancedcondition.

Eccentric turning and boringObjectives: This shall help you to• turn external eccentric diameter• bore internal eccentric diameter.

Turning external eccentric diameter, work held in a4 jaw chuck

The procedure of setting the work to turn the eccentric shafthas already been dealt with.

Further steps for turning are given below.

Set the tool to centre height with a minimum overhang.

Ensure that the tool tip is clear off the eccentric throw at thecommencement of the operation as shown in Fig 1.

Rough turn by successive cuts the eccentric diameterleaving approximately 0.8 mm in the diameter for finishturning. (Fig 1)

Set the finishing tool and finish turn to the diameter.

Face to length.

Remove the workpiece from the chuck.

Reverse and reset the job for turning concentric diameter.Use packing strips to protect the turned diameter held inchuck. (Fig 2)

Bring up the tailstock centre to the workpiece.

Release the chuck jaws, rotate the workpiece until thecentre dot of the concentric centre is in line with thetailstock centre. (Fig 2)

Check that all packing strips are in position.

Tighten the jaws.


Check the running of the concentric centre dot with the helpof the surface gauge.

Realign the jaws, if required.

Give each jaw a final tightening.

Make sure that the running of the concentriccentre dot is in line with the lathe axis.

Set the tool for rough turn.



52

Rough turn the concentric diameter.

Set the tool for finish turn, and finish turn the concentricdiameter.

Face to length.

Remove the eccentric turned job from the chuck.

Eccentric boring work held in a face plate

Truing has already been dealt with.

Rotate the face plate by hand to check that theclamps etc. are clear of the cross-slide andsaddle.

Centre drill.

Drill a hole for boring. Use a suitable coolant, and drill thehole on slow r.p.m. Keep an even pressure on the tailstockhand wheel. Take care when the drill is breaking through.

Set the boring bar/tool in the tool post.

Check and ensure that the length of the boring bar will clearthe bore and clamping bolts.

Rough cut bore.

Check the position of the hole from the outside diameter ofthe workpiece. Measurement should be taken on the linewhere maximum eccentricity occurs. (Fig 3)

Adjust the work position, if needed.

Finish bore to size.

Check the diameter.

Unlock the tool post and swing the boring tool clear.

Bring up the tailstock to support the workpiece.

Remove the clamps, retract the tailstock and remove theworkpiece from the machine. (Fig 4)

Return the tailstock to the extreme right hand end.

Remove all the counter-balance weights from the faceplate.

Eccentric turning on work held betweencentres.

Centre drill the marked dots at both ends. (Concentric andeccentric centres)

Mount the catch plate to the lathe spindle.

Clamp the carrier to the workpiece.

Grease the dead centre.

Support the workpiece between the eccentric centres foreccentric turning.

Ensure a positive drive from the catch plate to the carrier,and a minimum overhang of the tailstock barrel. Rotate thecatch plate by hand to check that the workpiece is in thecorrect plane. (Fig 5)

Clamp the tool in the tool post to correct centre height witha minimum overhang.

Rough turn eccentric diameter.

Take successive cuts until over half the diameter ismachined.

Check and determine the amount of metal to be removed.

Rotate the workpiece by hand and touch the tool to theworkpiece at the highest point of the throw and set thecross-slide graduated collar to zero.

Rough turn the eccentric diameter leaving 0.8 mm for finishturning. (Fig 6)

Turn length, leaving 0.4 mm for finish turning. (Fig 6)

Remove the workpiece and reset the job for concentricturning.

Clamp a suitable carrier to the eccentric diameter. Use softpacking strips between the finished diameter and thecarrier.



53

Hold the workpiece between the concentric centres.

Check that the workpiece is located in the correct plane.

Rough turn the diameter.

Finish turn the diameter to size.

Remove the workpiece and reset the job for finish turningthe eccentric diameter.

Clamp the carrier to the finished concentric diameter. Usesoft packings to protect the finished diameter.

Finish turn the eccentric diameter to size.

Finish turn the length to size.

This procedure applies only to jobs which willhave both the centre holes available forroughing and finishing operations.



54


Position boring using tool makers buttonObjectives: At the end of this exercise you shall be able to• make use of tool maker’s button• set and mark bore offsets• set on four jaw to bore offset bores.


55

Job Sequence

• Check raw material and deburr. • In 4 jaw chuck make blank of 10 x 75 x 75. (Fig 1)

• Mark two centre points of 26, 48.5 two points as perdrawing. (Fig 3)



56

• Drill to Tap to suit 4 BA.

• Fix tool maker’s button Ø 10.

• Set the centre to 25.88, 48.5 co-ordinate. (Fig 4)

• Fix job in 4 jaw chuck and tool maker’s button Ø 10 tolathe axis.

• After aligning remove tool maker’s button. (Fig 5)

• Drill and bore to dia Ø 17 H7+0.018

• Remove job and fix tool maker’s button in the othercentre.

• But the job against angle block build slips26 - 5 = 21 mm, adjust the roller against slip. Set thedial test indicator 0’ on surface plate and raise heightto 26 + 5 = 31 mm and compare with slips. Then checkand correct the tool maker’s button to 26 of co-ordi-nate centre. Similarly the distance 48.5 is set.

• Fix job in 4 jaw chuck and align tool maker’s button toaxis of lathe.

• Remove tool maker’s button.

• Drill and bore to dia 17 H7+0.018

• Remove job and deburr.



57

Skill Sequence

Checking the eccentricObjectives: At the end of this exercise you shall be able to• setting job for eccentric boring using tool maker’s buuton.

• Mark the eccentricity with ‘V’ block & Vernier heightgauge.

• Punch the centre marked & drill Ø 8 mm. (Fig 1)

• Tap M10 threaded hole. (Fig 2)

• Fit a tool maker’s button over this threaded hole. (Do nottighten fully)

• Adjust the botton position by building up by slip gaugeblock. (Fig 3)

• While positioning the button, tap gently as shown infigure. (Fig 4)

• After the button positioned as per the required dimensiontighten the screw fully.

• Finally mount the work in four jaw chuck & true it byusing dial test indicator.



58


Boring and stepped boringObjectives: At the end of this exercise you shall be able to• bore deep holes within close limits• check the bore dia using inside micrometer.


59

Job Sequence


• Hold the job in three jaw self centring chuck. Project-ing 110 mm outside the chuck.

• Face the end.

• Turn to Ø 40 mm for a maximum possible length.

• Reverse the job & face to maintain a length of 140 mm.


• Turn to dia 40 mm for a remaining length.

• Drilling step by step (first pilot drill of Ø 10 mm,Ø 16 mm & Ø 22 mm) for full length.

• Set the broing tool & bore to dia 20 H9 through hole.

• Check the hole by using inside micrometer.

• Step bore to Ø 30 H9 for a length of 100 mm (By givingseveral rough cuts & finally by finish cut)

• Check the stepped bore using inside micrometer.

• Deburr sharp corners if any. (Fig 1)



60


Cutting helical grooves (in bearing/bushes)Objectives: At the end of this exercise you shall be able to• finish the bore within close limits• cut the oil groove• chamfer the edges.

Job Sequence


• Face one end.

• Turn dia 38 mm for the maximum possible length.

• Chamfer the end 2 x 45º.

• Reverse the job and reset it.

• Face the other end and maintain to 60 mm length.

• Turn to ∅38 mm.

• Chamfer the end 2 x 45º.

• Centre drill the job with 60° type 1

• Drill the job with a pilot drill ∅12 mm

• Drill the job with a ∅20 mm drill bit.

• Bore the drilled hole to ∅24.75 mm and chamfer1 x 45º.

• Ream the job with a ∅25H7 machine reamer.

• Form the recess ∅29 mm x 3 mm width in after 6mm length. (as per drawing)

• Chamfer the other end of the hole after reversing andresetting.

• Check the dimensions after deburing.

• Hold the job in the chuck, select minimum speed.

• Hold the selected 1 mm grooving tool in the tool post.

• Change gear setting for 2 TPI.

• Cut the oil groove 1x1 on bore ∅25 to 50 mm length.

• Deburr the chips in the grooving area.


61


Turning & Boring of Split bearing (Using boring bar & Fixture)Objectives : At the end of this exercise you shall be able to• face the work squareness to all the sides• mark for 90º V groove• drill holes to required size• file and form V groove• drill hole at right angles to the axis of work.• split the bush in vertical position by hacksawing• set the job in fixtures.


62

Job SequenceTASK 1 : Split bushes


• Hold the raw material about 10 mm outside the chuckand true.

• Face one end.

• Reverse and hold work and true.

• Face and maintain a total length of 180 mm.

• Remove and hold work in vertical position and true it.(By reversing the two opposite jaws on 180 mm side)

• Face the job on all four sides maintaining squarness to30 mm size.

• Mark and punch for ∅12.5 mm drill hole location.

• Centre drill and drill ∅12.5 mm hole by holding the workon a vice.

• Mark for the 90º V groove as per drawing.(By reversing ‘V’ block, Vernier height gauge & Vernierbevel protractor)

• Remove the extra material with a hacksaw leavingsufficient metal for finish filling the ‘V’ groove.

• File and finish the ‘V’ groove and check with universalversion bevel protractor.

Note: Repeat the same sequence to completePart B component and made slot of 22 mm asper drawing.

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Skill SequenceSet the job in fixtureObjective: This shall help you to• set the job in fixture.

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TASK 2 : Boring of split bush


• Hold the job in a four jaw independent chuck and trueit.

• Face one end and turn ∅50 mm for 25 mm long.

• Finish turn ∅48 for 25 mm long.

• Reverse the job and true it.

• Face other end and maintain a total length of 70 mm.

• Turn remaining portion to ∅48 mm.

• Drill dia 10 mm through hole.

• Enlarge the through hole to ∅25 mm.

• Fix the boring bar in the tool post and bore ∅28 holefor the full length by giving successive cuts.

• Split the bush by hacksawing.

• File the saw cut surface and finish the surface flat.

• Hold the job in a fixture Ex. No. 3.3.105, Task 1.

• Finish turn ∅45 mm for maximum length.

• Reverse the job and hold in a fixture.

• Turn dia 45 mm in remaining length.

• Finish the bore dia 40 mm for the full length.

• Check the bore with help of inside micrometer.


63

Production & Manufacturing Exercise 3.4.106Turner - Multi Start Thread

Cutting Thread of 8 & 11 TPIObjectives: At the end of this exercise you shall be able to• inch thread RH & LH on long shaft• turn size jaws on lathe• drill & thread RH & LH


64

Job SequenceTASK 1 : Turning & Extrnal threading

• Check the raw material.

• Face and centre drill.

• In between centre turn Ø 25.4 mm, make undercut5 mm width through cut threads 1” BSW (11 TPI) to135 length.

• Similarly on other end turn turn Ø 15.375 mm, makeundercut 5 mm width, cut threads 5/8” BSW LH 11TPI)

• File flat 16 mm across flat to 15 mm width.

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TASK 2 & 3 : Turning bush and Internal threading• Check the raw material.

• On 4 jaw chuck in different setting make the blank tosize as per drawing.

• Mark the centre of boss and circle and punch.

• Align boss circle to lathe axis.

• Drill and bore to dia 13.1 mm for threading 5/8 BSW(11 TP1) LH of Task 3 and dia 22.85 mm for threading& BSW (8 TPI)

• Make threads and suit male part (Task 1)

• Remove, deburr and assemble part (Task 1,2,3) as perdrawing.


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65


Multi start thread cutting BSW (External & Internal)Objectives: At the end of this exercise you shall be able to• cut an external double start acme thread• cut an internal double start acme thread and match.


66

Job sequenceTASK 1 : External thread

• Hold the job in a 4-jaw chuck and face the ends,and maintain a total length of 150 mm.

• Centre drill the ends.

• Hold the job between the chuck and the centre.

• Turn Ø 40+0.5 mm for possible length, and step turn1 3/8” + 1 mm for 120 mm length.

• Form the radius groove for 7 mm width and maintainØ25 mm.

• Step turn Ø 25 mm for 20 mm length.

• Chemfer the ends.

• Reverse and hold the job on 1 3/8” + 1 mm and true.

• Finish turn Ø 40 mm, with the work supported withdead centre.

• Knurl on Ø 40 mm and chamfer the edge 1.5 x 45°.

• Reverse and hold on knurled dia. true and support withdead centre.

• Finish turn Ø 1 3/8 mm to cut the thread.

• Make chamfer of 3 x 45°.

• Arrange the gear train for 4 TP1 pitch thread.

• Arrange the thread chasing dial.

• Hold the BSW thread cutting tool in the tool post tocentre height.

• Swivel the compound slide 29.5” to the right from thevertical position, and set the tool at right angles to thework axis.

• Cut the external BSW thread by the half includedangle method for first start.

• Index the tool for second start & finish the thread.

• Deburr sharp corners.

• Check the formation with screw pitch gauge & dimen-sion with screw thread micrometer.

TASK 2 : Internal thread

− − − − − − −− − − − − −− − − − − −− − − − − −− − − − − −

• Hold the job in 4 jaw chuck projecting 35 mm.

• True it by using surface gauge.

• Set the facing tool & face the end.

• Set RH Turning tool & turn to dia 40-0.2 for a maximumlength.

• Chamfer the end to 3 x 45°.

• Form knurling & maintain dia 40 mm for maximumpossible length.


• By drilling & boring maintain internal dia equal to theroot dia of thread.

• Chamfer the end to 3 x 45°.

• Set the thread chasing dial.

• Cut first start of thread.

• Index the thread chasing dial & cut second start.

• Check for the formation by assembling with Part A(Task 1)

• If any variation, again give cuts by indexing.

• Finally match wtih Task 1 job.

• Set the parting tool & part off to a length of 30+0.2.

• Set the joh & face it to maintain 30 mm length.

• Chamfer the end to 3 x 45° (Both external & internal)

• Deburr all sharp corners.

Skill Sequence

Cutting external ‘V’ thread by half angle methodObjective: This shall help you to• cut external ‘V’ thread by the half angle method.

The plunge cut method of cutting ‘V’ thread is limited for finepitch threads where the depth of cut is less, and thesuccessive cuts to be given are comparatively less. Fur-ther in the plunge cut method, the tip of the tool as well asboth the flanks will be removing material from the workpiece.This causes heavier load on the cutting tool’s cutting face

which may result in the breaking of the tool tip, damagedthread and reduction in the tool life. To overcome thesedefects, the half angle method is adopted to cut threads.

The steps required are given here.

Check the diameter of the workpiece to be threaded byreferring to the drawing.



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To provide thread clearance, it is good practiceto turn the diameter of the workpiece under-size depending upon the pitch.

Set the lathe spindle speed to about one fourth of theturning speed.

Set the gearbox according to the pitch of thread to be cut.

Swivel the compound slide to 90° from the horizontalposition to bring it in line with the cross-slide.

Swivel to the right 1° less than the half included angle of thethread if it is a right hand thread. (Fig. 1)

The angle to which the compound rest is setaffects the cutting action of the cutting tool byproducing a shearing action on the trailingedge of the tool. This produces a smooth cut.

Set the tool in the tool post with a minimum overhangperpendicular to the axis and also set with a centre gauge.(Fig 2)

Mark out the length of the workpiece to be threaded.

Chamfer the end of the workpiece surface with the leadingedge of the cutting tool to a depth, just greater than theminor diameter of the thread to be cut.

Advance the cutting tool to the work surface by operatingthe cross-slide hand wheel.

When the tip of the tool just touches the work surface, stopfurther advancement and set the cross-slide and com-pound slide graduated collars to zero.

Move the carriage to the right until the end of the tool clearsthe work.

Feed the tool in about 0.1 mm using the top slide handwheel.

Engage the half nut referring to the chasing dial.

Take a trial cut along the workpiece to be threaded.(Fig 3)

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At the end of the trial cut, withdraw the tool immediately,winding it clear off the workpiece by operating the cross-slide hand wheel and simultaneously reversing the ma-chine. (Fig 4)

Allow the carriage to move to the right till it is cleared fromthe end of the work, and stop the machine. (Fig 5)



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Check the thread formation with a pitch gauge.

Advance the tool by the cross-slide hand wheel till zeroposition.

Give depth of cut with the top slide handle.

Start the machine and allow the tool to cut the thread.(Fig 6)

Use plenty of coolant during threading.

Repeat the steps till the required depth is reached.(Fig 7)

At the end of each cut, the tool is withdrawnfrom the work by the cross-slide hand wheel,and the carriage is brought to the starting point.The cross-slide hand wheel is brought to zeroposition and a depth of cut is given by the topslide.

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Cutting internal ‘V’ thread by half angle methodObjective: This shall help you to• cut internal metric R.H. ‘V’ thread by the half angle method.

Internal ‘V’ threads are generally cut by the plunge cutmethod even for coarse pitch threads. As in the case ofexternal ‘V’ thread cutting, the internal ‘V’ thread tool alsohas to undergo heavy cutting load during the internalthreading operation. But as the tendency of the tool is tospring, the breakage of the tool is greatly avoided. Toprolong the tool life and to have a better thread finish evenfor internal threading, the half angle method is followed.Following is the procedure for internal threading in a blindhole.The work is drilled and bored to the core diameter of thethread.An internal recess is formed at the end of the blind hole. Thehole itself must be sufficiently long enough to clear off theboring bar. The width of the recess formed must be wideenough to allow the cutting tool to clear off the thread andthe diameter of the recess must be larger than the majordiameter of the thread.The width and diameter of the recess will generally be givenin the drawings, but in case it is not, it is left to thediscretion of the operator himself to determine them.(Fig.1)

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Counterbore the outer end of the hole for a length of 2 mmand a diameter equal to the major diameter of the thread.

This is possible only if the total length of thework is sufficiently more than the finishedlength.

Swivel the compound slide 29° to the vertical towards leftfor cutting a right hand thread. (Fig 2)



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Arrange the quick change gearbox levers for the pitch of thethread to be cut.

Mount the boring bar with the ‘V’ thread tool in the tool post,parallel to the lathe axis, and set the point of the cutting toolto the centre and with the centre gauge. (Fig 3)

Mark on the boring bar an indication for the required entryinto the bore to cover up the thread length.

Add half the recess width to the length of thethread to be cut, and then mark this distance onthe boring bar back from the centre line of thecutting tool.

In-feed the point of the cutting tool until it lightly touches thework surface at the outside end of the bore.

Set the cross-slide and the top slide graduated collars tozero.

Position the tool to clear off from the work.Give a depth of cut by the top slide hand wheel by rotatingthe handle anticlockwise.

Engage the half nut and allow the tool to have the trial cut.When the tool has entered up to the scribed mark on thebar, release the tool by rotating the cross-slide hand wheelclockwise, simultaneously reversing the machine to makethe carriage move to the starting point.

Rotate the cross-slide hand wheel in the anticlockwisedirection to bring to zero mark.Give a further depth of cut by the top slide hand wheelrotating in the anticlockwise direction.

Give successive cuts and finish the thread.

The last depth of cut should make the tool tip tojust touch the counterbored hole at the mouthof the hole.

Repeat the same last cut twice or thrice.Check with the mating part for the fit.

Face off the counterbored end, if sufficient material is thereand chamfer to match.

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Multi start thread cutting (Metric) (External & Internal)Objectives: At the end of this exercise you shall be able to• holding and by using the job on 4 jaw chuck• set the job in between centre• set the face plate for cutting multi start thread.


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Job Sequence

Part A - External thread• Hold the job in a four jaw chuck and face both the ends

maintain total length of 100 mm.

• Centre drill at the ends and hold the job between cen-tres using a drilling plate having slots milled at 180°and a bent tail carrier.

• Turn the outer dia 32 mm to full length and chamfer theends.

• Form the groove Ø 25 x 7 mm leaving 30 mm distancefrom the end and form the radius 2 mm.

• Arrange the gear train to cut 6 mm lead threads on thejob.

• Cut the first start thread to half the depth.

• Change the setting the bent tail of the dog carries withopposite slot of the face plate.

• Cut the 2nd start thread to full depth by giving succes-sive cuts.

• Reset the job for completing the 1st start thrreads tofull depth.

• Cut the first start threads to full depth by giving suc-cessive cuts.

Part B - Internal thread• Hold the job in four jaw chuck projecting 35 mm and

true it.

• Face the end and turn to Ø 40-0.2 for maximum length.

• Make centre drill.

• By drilling and boring maintain internal dia equal to theroot dia of thread.

• Chamfer the ends 3 45° for both external and internal.

• Set the internal threading tool and set the change gearsto cut a feed of 6 mm (3mm pitch of double start)

• Cut the first start thread to half the depth.

• Second start thread is to be cut by indexing the threadchasing dial.

• Cut the thread to full depth by giving successive cuts.

• Again reset by indexing to the first start finish the threadfull depth.

• Match the job with Part A.

• Deburr all the sharp corner.

• Set the knurling tool and for knurling to maintain dia 40mm for 30 mm length.

• Set the parting tool and part off to a length of 30+0.2mm.

• Hold the job and face to maintain a length of 30 mm.

• Chamfer end to 3 x 45° (both external and internal)

• Remove the sharp corner if any.

• Assemble both external and internal.

Skill Sequence

Double start thread by thread chasing dialObjective: This shall help you to• cut multi-start threads using thread chasing dials.

This may be used to produce 2, 4 and 8 starts mostly withodd numbered leads such as 1,3,5,7 etc. or fractional leadssuch as 1/1.5.

The steps for cutting double start threads of 1/7" pitch ona lathe having 4 TPI lead screw are as follows.

Set the lathe for cutting a screw thread of the given lead.

Mount the workpiece.

Engage the carriage half nut on a numbered line on thethread chasing dial.

Make the first cut of the first start threads and return thecutting tool to the starting position of the threads.

Set the cross-slide graduated collar to zero.

Engage the carriage half nut on an unnumbered line onthe thread chasing dial and take the first cut of the sec-ond start threads.

Engagement of the half nut at this position automaticallycentres the cutting tool half way between the path of thefirst start threads.

Give the same depth of cut for both the starts alternativelytill the full depth is reached.



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Multiple thread by face - plate methodObjective: This shall help you to• cut multistart threads by the face-plate method.

This method may be used only if the face–plate slots areaccurately machined. (Fig 1)

If, for example, a double start Vee form thread having 12threads per inch and a 1/6" lead is required, the proce-dure is as follows.

Set up the lathe for thread cutting.

Set the gearbox levers for 6 threads per inch.

If a change gear train has to be arranged, determine thechange gears using the formula

Lead of workpiece Driver

Lead of lead screw Driven

Calculate the depth of the thread to be cut for 12 threadsper inch.

Face–plate with slotsThe slots numbered as 1, 2, 3 and 4 are to be used forcutting the double start threads.

Cut the first start threads to within 0.010" inch of therequired depth. The depth of cut is given by the top slide.

Make a note of the graduation on the top slide gradu-ated collar, and without moving the cross-slide handle,withdraw the cutting tool from the workpiece by the topslide hand wheel rotation.

Stop the lathe and bring the carriage to the starting posi-tion.

With the driving attachment still fitted to the workpiece,remove the workpiece from the lathe, turn it through 180°and set it back in the lathe with the driving attachmentfitted in the opposite slot in the drive-plate.

Start the lathe and engage the half nut.

Feed the compound slide towards the workpiece for thedepth of cut until the cutting tool just contacts the workpiecesurface.

Using the compound rest for successive depths, cut thesecond start thread to the calculated depth.

Without moving the setting of the crossslide and top slideremove the workpiece and turn it through 180° as beforeand reset in the lathe.

Give the finishing cut on the first start threads.



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Multi start square thread cutting (External and Internal)Objectives: At the end of this exercise you shall be able to• set and index the driving gear for cutting double start square threads• grind the correct width of tool required as per the pitch for cutting double start square threads, external and

internal• cut internal double start square threads and match the male part.


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Job sequence

TASK 1: Plain turning and double start square threading(External)

• Hold the job in a four-jaw chuck, true and face both endsand maintain a total length of 160 mm.

• Centre drill both ends.

• Remove the four-jaw chuck and mount a driving plate.

• Insert the headstock centre with the spindle sleeve andthe tailstock centre.

• Hold the job in a suitable carrier in between centres.

• Turn dia. 38 h8 to a length of 125 mm.

• Turn Ø 24 mm to a length of 35 mm.


• Finish radius groove R2 to a length of 6 mm at 35 mmlength.

• Finish chamfer 1 x 45° at the end of 20 mm dia.

• Reverse the job and hold in a suitable carrier with softmetal packing.

• Turn Ø26 – 0.08 to a length of 110 mm.


• Chamfer 1 x 45° at the end of Ø 22 mm. Chamfer 1 x45° at the collar on Ø 38 h8 on both sides.

• Undercut to core dia. for 6 mm width.

• Set the square threading tool, to correct centre height.

TASK 2: Bush turning and Internal square threading• Cut the first start to a length of 99 mm.

• Index the driving gear exactly for cutting the 2nd start.

• Cut the second start to a length of 99 mm.

PART B

• Hold the job in a four-jaw chuck, true and face both endsmaintaining a total length of 40 mm.

• Drill Ø18 mm through hole.

• Bore the drilled hole to the size of the core diameter.

• Grind the internal square threading tool to a width of 1/2 x pitch + 0.02 mm.

• Set the internal square threading tool to correct centreheight.

• Cut the first start through.

• Cut the second start through.

• Match the job with the male piece.

• Hold the male and female pieces assembled togetherin between centres.


• Diamond knurl to a length of 40 mm.

• Chamfer 2 x 45° at both ends.

Skill Sequence

Square threadObjective: This shall help you to• cut a square thread.

Check the diameter of the portion to be threaded asindicated in the drawing.

Chamfer the edge of the job to 2 x 45 degree.

Set up the gearbox to cut the required pitch of thread, andhand of thread.

Set the square threading (roughing) tool in the tool post withits height to the centre height of the lathe.

Set the tool square to the axis of the job with the squarethread gauge. (Figs 1 and 2)

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Care is to be taken to prevent overhanging of tool from theholder to avoid chatter.

Set the spindle speed about 1/4th of normal turning.

Cut the square thread, by repeated successive depth ofcuts to reach 3/4th width and depth of thread. (Fig 3)

Set the finishing square thread tool for finishing cuts.

Cut the square thread to full depth and full width by takingsuccessive cuts to complete the required thread form.

Deburr and check the square thread using a square threadgauge.

Grind an external threading toolObjective: This shall be able to• grind an external square threading tool.

Determine width and angles required for grinding theexternal square threading tool.

The side clearance of the square threading tool is of primeimportance to prevent the tool from interfering or rubbingagainst the vertical flank of the thread. As a rule, theforward side clearance angle (a1) is determined by adding1° to the helix angle of the thread and trailing side clearanceangle is obtained by subtracting 1° from the helix angle.(Fig 1)

α 1 = 1° + Helix angle of thread

and

α 2 = Helix angle of thread - 1° where, helix angle (α)

The width of the nose of the square threading tool shouldbe equal to half of the pitch of the square thread to be cut.W = 0.5 x p

Grind the front flank of the tool to get the front clearanceangle 6° to 8°.(Fig 2)



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Grind the forward side flank of the tool to obtain side reliefangle 1° to 2° and forward side clearance angle α 1. (Fig 3)

α1 = α + (1° to 2° )

Grind the trailing side flank of the tool to maintain the siderelief angle 1°-2°, trailing side clearance angle a 2 (a2 = a-1°) and the width W (W=0.5 x p). (Fig 4)

Deburr and check the width of the angles using a verniercaliper and bevel protractor.


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Making Half Nut as per standard lead screwObjectives: At the end of this exercise you shall be able to• turn eccentric stepped boss and boring• spliting twohalfs and setting on fixture• boring and threading of ACME 32 x 5 internal thread• setting and forming R 56 on both sides.


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Job Sequence• Check the raw material to the size of 40 x 55 x 105

and deburr. (Fig 1)

• Fix on 4 jaw chuck, in different setting face all facesone by one and maintain size 35 x 50 x 100 (Fig 2,3,4)

• Deburr corners.

• Draw the shape on paper.

• Paste paper over the blank punch dots over the markedlines of arcs and circles and axis line of bore. Punchdots on Ø 22 circle and axis lines for setting and truingof eccentric bore. (Fig 5)

• Set the job blank on 4 jaw chuck and align circle cen-tre to lathe.

• Turn Ø 44 x 20 and form R 8.

• Drill and bore to dia 22. (Fig 6)

• Remove the job from chuck.



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• Slit Saw/Hacksaw into two pieces at bore axis line.(Fig 7)


• Fix face plate and clamp two holes opposite to eachother and align R 56 radial dot punch mark to latheaxis.

• Bore the form R 56 radius. (Fig 8)

• File flat the mating surface.

• Fix the turning fixture bracket in face plate slot andalign ‘V’ centre to lathe axis.

• Clamp, true it to lathe axis. (Fig 9)

• Depth of thread = 1/2 P + 0.01

= 1/2 x 5

• Bore to diameter = 26.50.

• Set threading tool for ACME thread.

• Cut threads to 2.75 deep.

• Finish threads remove two havlves and deburr.





Documents

Turner (NSQF) - 3rd SEM - Practical Contents · Shri. D.N. Srinivasa Shetty _ Junoi r Tranini g Oceiff r Govt. ITI, Bangalore -29. Shri. Chandrahasa _ Junoi r Tranini g Oceiff r Govt